Mold for forming containers



Au Z 1927.

g w. H. OLIVER ET AL.

MOLD FOR FORMING CONTAINERS Fiied Nov. 22, 1925 4 sheets-sheet 1.

a .Il

.Lern

. INVENTORS.- vemw fla/wld, Gbe/z, BY S. Cuv-v 'l OMA oRNEY Aug. 2,1927. 1,637,532

w. H. OLIVER ET Al.

HOLD FOR FORMING CONTAINERS Filed Nov. 22, 1923 4 Sheets-Sheet 2 lINVENToRs.' lunaw y am J- cuv'v Aug. 2, 1927. '1,637,532

W. H. OLIVER ET AL MOLD Foa FORMING CONTAINERS Filed Nov. 22, 1923 4Sheets-Sheet 3 kik: Y

Aug; 2,1927.

W. H. OLIVER ET AL MOLD FOR FORM'ING CONTAINERS Filed NOV. 22, 1923 4Sheets-Sheet 4 INVENTORS: Z ZZ: i i! WMA TTORNEY Patented Aug. 2, 1927.

'WILLIAI HAROLD OLIVER AND EDWIN 8. CULVELXOF OAKLAND, CALIFORNIA.

noma ron romnua CONTAINERS.

Application led November 22, 1928. Serial No. 676,232.

Our invention relates to an im roved mold whereby containers may be`ormed from wood pulp or other suitable material.

The principal object of our invention 1s to rapidly form containerswhich may have either a constant or variable thickness, and which willbe properly drained and, ressed to retain their form when remove fromthe mold. y

A further object is a mold so constructed that surplus water is pressedfrom the pulp, during which process thefibers in the pulp `will interlayorfelt as the water is being removed.

Another object is a mold in whichsurplus water, as it is pressed fromthe pulp, is swept away from the compressed surface by a current of airand thus picked up and removed out of contact with .the adjacentcontainer surface.

Another object is a mold in which a ilexible or rubber diaphragm is usedin forming the container.

Other objects will appear from the drawings and specification whichfollow.

Figure 1 is a cross section through one form of mold built in accordancewith our invention.

F ig. 2 is a bottom view of the core, within f said mold.

Fig. 3 is a cross section of Fig. 1 on thel line IIL-lll thereof.

Fig. 4 is a cross section through another form of mold built inaccordance with our invention.

Fig. 5 is a cross section of Fig. 4 on the line II-II thereof. y

Fig. 6 is a section through ,our extractor employed in removing thecontainer from the mold shown in Fig. 4 and Fig. 5. y

Referring to the mold shown in Figs. 1, 2 and 3, an outer casing or bodyportion of the moldis shown at 1, to which pulp is Supplied'by thecylindrical filling chamber 2 carryingthe.conventional piston 3 to whichis attached the hollow piston rod `4 and within which rod is the pipeconnection 5 extending through the piston 3 into a core 6 which isattached to the lower end of said piston. The core 6 has outer sidechannels 7 and bottom ports 8 and channels 21 communicating with acentral compartment 9. Surroundin the outer channelled surface of thecore an likewise attached to the iston, is a screen 10. At 11 is shown aflexib e diaphragm which may be made of rubber or other suitablematerial, said diaphragmibeing positioned within the body portion 1 andexterior to said core 6 and screen 10.

In making a container, the piston 3 to which is attached core 6 andscreen 10, together with all parts within said core is raised up and outof filling chamber 2. AA vacuum or negative pressure is then appliedthrough openin, 12 into the chamber 13,

which draws t e flexible diaphragm 11 against the interior walls of thebody portion 1. A predetermined quantity of pulp of suitable materialandconsistency, but usuall in a comparatively fluid state is admittethrough the filling chamber 2 into the expanded iexible diaphragm 11..The piston 3 with its attached parts is than pushed by some suitablemeans down filling chamber 2 to a predetermined point, as shown in Fig.1.

During the downward movement of piston 3 a vacuum or negative pressureis applied to Lthe central compartment 9 of the core 6 through the pipeconnection 5 within the piston rod 4. The pressure caused by thedownward movement of the piston 3, together with the negative pressurewithin the compartment 9 causes water from the pulp 24 to be forcedthrough the screen 10 into the channels 7 of the core 6. Suitableilexible valves 14"are depressed due to the unbalanced-pressures whichvalves admit atmospheric air from the open space in filling chamber 2above the piston 3 through passages 15 into the channels 7. in the core.Also due to unbalanced pressures the valve mechanism 16, 17, 18, 19 israised so as to seal ports 20 by valves 26.

nThe atmos heric air rushes down channels 7 in back o screen 10 sweepingaway the water forced through the screen and carrying it in channels 7and bottom channels 21 through connecting ports 8, around lower valves22 (also a portion of valve mechanism 16, 17, 18 and 19), and over valvelip 23 and thence up through pipe 5.

After the piston 3 has reached the position shown in Fig. 1, thevnegative pressure is discontinued through opening 12 and insteadpositive pressure admitted through said opening into the chamber 13.This positive pressure causes the flexible diaphragm 11 to furthersqueeze the pulp 2,4 towards the vscreen`10, until said diaphragmreaches the position shown in Fig. 1. The continued rush of .air throughpassages 15 and chanlOl nels 7 carries away with it all water remainingin the mesh of the screen or channels. In the meanwhile the materialsuspended in the liquid of the pulp has been laid up against the screen10 in such a way that the libere will interlay or felt. v

After a suitable length of time, the positive pressure maintained inchamber 13 is rei leased and a negative pressure applied which causesthe .flexible diaphragm ll to resume its former position against theinterior walls of the body of the mold. Piston 3, with Y negativepressure still applied to Vthe interior chamber v9 of core 6, is raisedup and out of the filling chamber 2. 'lhe negative pressure appliedthrough the pipe 5 is then released which causes valves 22 to drop,sealing ports 8. t

A positive pressure is then admitted through the inner passage 25' olthe piston rod4 into the central chamber tl'of the core' 6. Due Vtounbalanced pressures the valves seal the passages l5 and a positivepressure is 'built up within the central chamber ol the core,therebyvcausing the tinished cont-ainer to be released from the screenl() and" dropped ontoa suitable conveyor. At'ter the container' has beenso released a greater pressure m'ay be admitted through the passage 25to the inside of the core, thereby removing any dirt or smallliber'which may have collected in the screen 10- or channels 7 and 2l.

Slight variations may be made without departing from the scope of ourinvention,

as tor instance the ports 20 may be at other p places than shown and thevalves 22 and 2G may be omittedaltogether. It will also be understoodthat the form of mold may vary so that containers ot any suitablelshapemay be made, and that the diaphragm may be of rubber, silk or variousother materials.

Likewise the screen may be of the ordinary mesh variety of any materialor otherwise perforated.

In Figs. 1` 2, and 3,' we have'shown the flexible diap ragni squeezingthe pulp towards the screened core, whereas in Figs. 4 and 5 theflexible diaphragm is shown. squeezing the pulp away from the outside ofthe core and toward the insideof the screen. In `the former figures thediaphragm is shown outside, and the-screen inside the container, whereasin the latter iigures the `diaphragm is shown inside and the screen outside the container, a mere change in location.

In Fig. l4 the body portion of the mold is shown at 27 to whichpulp issupplied by a similar'illing chamber 28,l to that shown in Fig. 1, andwithin which chamber the conventional piston 29 and hollow piston rod 30operate. Mounted with the body portion 27 is a screensupporting mold 31having a plurality of openings which may be in the form of long slots 32with top and bottom ports 33 communicating with a suitably sized chamber34 surroundin v the mold 31 so that liquid may be drained tiroughopening 35 at the bottom of the body portion as by a Vacuum pump notshown but well known.

The core lis shown at 36 about the outer surface of which normallyreposes the flexible diaphragm 37, the core land diaphragm being fixedto the piston. The core has a plurality ot' holes 38 whereby pressuremay be exerted against the diaphragm to cause the latter to expandagainst the pulp.

In the operation of the mold shown in Figs. 4 and 5, a measured quantityof pulp enters the screen supporting mold after which the pistoncarrying the core and diaphragm is torced downward through the pulp 39until it reaches the position shown in Fig. 4. During thisdownwardmovement of the piston, liquid is pressed out of the pulp, through thescreen 4t) and drained through the slots 32 and ports 33, while thematerial suspended in said liquid will be laid up against the screen,allowing the fibers to -interlay ortolt. During Vthis step of theln'ocess a negative pressure may be applied through opening 35 tochamber 34.

After the piston has reached the position shown in Fig. 4 the flexiblediaphragm is expanded by the application of positive pressure enteringlthe. center of the core through the hollow piston stem and transmittedto the diaphragm through the perforations 38. 'lhe expanding diaphragmwill squeeze the pulp so that the inner surface thereof will assume theposition indicated by the. dotted line 4l. This squeezing action willforce additional liquid into the chamber 34 which is withdrawn throughoutlet 35. A negative pressure may also be applied through outlet 35either before, simultaneously with, or after the pressure has beenapplied through thc piston rod as the pulp used for making the containerrequires, and the application of such negative pressure is for thepurpose of removing as much of the remaining liquid as possible.

By means of an inlet 42 and passages 43, a current of air is createdwhich rushes down through the chamber" 34 past slots 32 and ports 33 andacross the exposedareas of the screen through all these openings,causing some of the liquid in theA ports and slots to evaporate, butalso sweeping away a larger portion which might otherwise remain thereinthrough capillary attraction.

After a predetermined length of time the positive pressure a pliedthrough the piston rod` is discontlnued4 so that the dia` phragm isreleased from the interior of the container and resumes its normalposition. The negative pressure through the chamber 34 may also bediscontinued. The pistou ui'ut with the core and diaphragm are rellt)moved leaving the squeezed container within the. screen and supportingmold.

The extractor shown in Fig. 6 is then inserted so that the outer surfaceof its mesh 44 is in contact. with the inner surface of the container'and a negative pressure applied through stem 45 and a positive lowpressure or puiil applied to chamber 34 through connection 4G. whichpuff releases the. container from the surface of the screen. Theextractor is removed, with the container held thereto by means of thestill applied negative pressure, and the container finally is releasedfrom the extractor by discontinuing this negative pressure and theapplication of low pressure air through the stem.

Vhile wehave shown two variations of our invention, other forms willsuggest themselves to those Who are skilled in this art, withoutdeparting from the gist of our invention, and Wc desire to be understoodas claiming all such variations.

1.. 'I` /he, process ot' forming containers or f the. like whichconsists of introducing pulp in a mold member, inserting a core memberwithin said pulp, squeezing the pulp by means of a flexible diaphragmadjacent one of said members in the direction of the other member,carrying away the surplus liquid squeezed from the pulp by a current ofair passing through drainage means in the member toward which the pulphas been squeezed.

2. The process of forming containers or the like which consists inintroducing pulp between a relatively rigid and perforated concavemember and a flexible diaphragm, transmitting pressure against saiddiaphragm so as to squeeze the pulp against the inner walls of saidrelatively rigid member, releasing the pressure and removing saiddiaphragm. inserting an extractor and introducing pressure through theperforations ot' said relatively rigid member, and negative pressurefrom said extractor for the purpose A form,

of removing said container from the concave member.

3. The process ot' forming containers or the like which consists ofintroducing pulp,

in a mold member. inserting a relatively rigid core ineinberwithin saidpulp, squeezing said pulp in the direction of one of said members bymeans of a flexible diaphragm against which pressure has been conveyed,draining the surplus liquid from said pulp, releasing thepressureagainst the flexible diaphragm a'nd introducing positive counterpressure against. the opposite side of said container to liberate theymolded container.

4. The process of forming containers or the like which consists ofintroducing pulp in a lnold member. inserting a relatively rigid coremember within said pulp, squeezing sa'id pulp in the direction of one ofsaid members by means ot a flexible diaphragm against which pressure hasbeen conveyed,

.draining the surplus liquid from said pulp,

by a current of air passing through drainage means in the member towardwhich the pulp has been squeezed. releasing the pressure aginst theflexible diaphragm and introducing positive counter pressure aginst theopposite side ot said container to liberate the molded container.

5. In a mold for forming containers and the like from Wet pulp, a moldmember having a plurality of drainage ports for draining moisture fromthe pulp being molded. a perforated form in spaced relation to said moldmember. a screen against said mold member, a flexible diaphragm normallyspaced from said screen, means for directing pressure through theperforations of said an outlet connection Itroni said drainage ports,and means for conveying a current of air along said drainage ports. tosaid outlet connection.

WILLIAM HaRoLD oLivER. EDWIN s. CULVER.

i el!

